Injection molded plastic product design method involves computer-aided determination of tool clamping force and use of the force to optimize design factors

摘要

The tool clamping force for injection of a resin molding of a specific shape is determined using a computer aided optimization process. The molding design may then be determined on the basis of the resulting tool clamping force. A process parameter for determining flow in runners to a molding cavity is used as a variable parameter for determining tool closure force. A preferred parameter is one which controls operation of flow control valves for each runner. Flow control valves are generally slide valves which can be moved into fully open or fully closed positions. The parameter is optimized using the condition that at least one slide valve is kept open at each point in time during the filling stage. Material and molding thickness distribution are based on the clamping force determined by the optimization process. Thickness distribution, in particular, is based on the tool clamping force determined under forced conditions. Independent claims are included for: a) an injection machine used for molding the product designed by the claimed method which has an injection unit for feeding molten resin into a tool cavity via runners, a data storage unit for storage of the molding parameters determined by the computer supported optimization process and a control unit for operating the injection machine according to molding parameters for a given tool closure force; b) a process for manufacturing a resin product designed by the claimed method and injection molded using an optimized condition.